<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

        <input type="text" id="userId">
        <input type="text" id="classId">
        <input type="submit" value="提交" id="submit">

<!--    要想构造一个json的请求，不在使用form。使用ajax-->




    <script src = "https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script>

    <script>
        // $.ajax({
        //   type:'post',
        //   url:'method',
        //   success: function (body){
        //     console.log(body);
        //   }
        // })

        let userIdInput = document.querySelector('#userId');
        let classIdInput = document.querySelector('#classId');
        let button = document.querySelector('#submit');
        button.onclick = function (){
            $.ajax({
                type:'post',
                url:'postJson',
                contentType:'application/json',
                data:JSON.stringify({
                    userId:userIdInput.value,
                    classId:classIdInput.value
                }),
                success: function (body){
                    console.log(body);
                }
            })
        }

      </script>

</body>
</html>